Growth and joint symptoms in children treated with nalidixic acid.

To analyze the effects of quinolones on growth and joints in children we identified 78 patients who had been receiving nalidixic acid for 116 days on the average (range, 3 to 570 days) from a random sample of 3094 of 16,409 children treated with long term medication because of recurrent urinary tract infection. Two controls per each index case, matched for sex and the age at which the first medication for recurrent urinary tract infection occurred, were chosen. Frequency of joint symptoms and examinations or possible treatments for arthropathies were similar in the index (n = 44) and control (n = 62) cases. Detailed growth data were analyzed from 39 case-control pairs after the mean follow-up time of 19.6 years (range, 14.8 to 24.7 years), and no growth disturbances were found. The final heights (age, > 18 years) of the index and control cases were similar (n = 31 case-control pairs). We conclude that nalidixic acid does not cause arthropathies or hamper growth in children, which supports the suggestion that at least short treatment periods with quinolones are safe.